1. Field of the Invention
The present invention relates to an antenna, and more particularly, to an antenna having flexible design for effectively adjusting radiation pattern or operating frequency band thereof.
2. Description of the Prior Art
Portable electronic products with wireless communication functionalities, e.g., laptops, tablet PCs, personal digital assistants (PDAs), etc., utilize antennas to emit and receive radio waves for transmitting or exchanging radio signals, so as to access wireless network. With the increasing demand for the appearance and functionalities of portable electronic products, available space for each component in a portable electronic product is getting compressed, so is the available space for an antenna device.
In addition, with the evolving of wireless communication technology, a single electronic product maybe equipped with multiple sets of antennas for supporting a Multi-input Multi-output (MIMO) communication technology or transmission requirements of multiple communication systems. When an electronic product is equipped with multiple sets of antennas within limited space, one of the fundamental communication requirements is to assure that these antennas have good isolation so that they are not affected with each other. Thus, it is a common goal in the industry to reduce coupling effects between these antennas. However, the antenna design becomes more difficult for improving the antenna isolation while the antennas are disposed in limited space.
On the other hand, if a housing of a portable electronic device is covered by metal, the antenna efficiency may be easily affected. In such a condition, if the antenna pattern can be adjusted more easily, the portable electronic device may be adapted to different application environments and the antenna efficiency may be increased.
Therefore, it is a common goal in the industry to design antennas which conform to transmission requirements and have adjustable radiation patterns or operating frequency bands, while taking the size and functions into account at the same time.